On 17/11/2025 14:30, Jinjie Ruan wrote:
> [...]
>
> @@ -2386,19 +2384,27 @@ int syscall_trace_enter(struct pt_regs *regs)
> if (secure_computing() == -1)
> return NO_SYSCALL;
>
> - if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
> - trace_sys_enter(regs, regs->syscallno);
> + /* Either of the above might have changed the syscall number */
> + syscall = syscall_get_nr(current, regs);
> +
> + if (test_thread_flag(TIF_SYSCALL_TRACEPOINT)) {
> + trace_sys_enter(regs, syscall);
>
> - audit_syscall_entry(regs->syscallno, regs->orig_x0, regs->regs[1],
> + /*
> + * Probes or BPF hooks in the tracepoint may have changed the
> + * system call number as well.
> + */
> + syscall = syscall_get_nr(current, regs);
> + }
> +
> + audit_syscall_entry(syscall, regs->orig_x0, regs->regs[1],
> regs->regs[2], regs->regs[3]);
>
> return regs->syscallno;
It would be good to align the return with the generic version as well.
> }
>
> -void syscall_trace_exit(struct pt_regs *regs)
> +void syscall_trace_exit(struct pt_regs *regs, unsigned long flags)
> {
> - unsigned long flags = read_thread_flags();
> -
> audit_syscall_exit(regs);
>
> if (flags & _TIF_SYSCALL_TRACEPOINT)
> diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
> index aba7ca6bca2d..6e3fe760e0bb 100644
> --- a/arch/arm64/kernel/syscall.c
> +++ b/arch/arm64/kernel/syscall.c
> @@ -124,7 +124,7 @@ static void el0_svc_common(struct pt_regs *regs, int
> scno, int sc_nr,
> */
> if (scno == NO_SYSCALL)
> syscall_set_return_value(current, regs, -ENOSYS, 0);
> - scno = syscall_trace_enter(regs);
> + scno = syscall_trace_enter(regs, regs->syscallno, flags);
Nit: could use scno instead of regs->syscallno.
- Kevin
> if (scno == NO_SYSCALL)
> goto trace_exit;
> }
> @@ -143,7 +143,8 @@ static void el0_svc_common(struct pt_regs *regs, int
> scno, int sc_nr,
> }
>
> trace_exit:
> - syscall_trace_exit(regs);
> + flags = read_thread_flags();
> + syscall_trace_exit(regs, flags);
> }
>
> void do_el0_svc(struct pt_regs *regs)
